Wireless signaling apparatus



June 23, 1931. E. KARPLUS WIRELESS SIGNALING APPARATUS Filed March 11,1929 Patented June 23, 1931 UNITED STATES PATENT OFFICE EDUARD KARPLUS,OIE BERLIN-T'EMPELHOF, GERMANY, ASSIGNOR '10 0. LORENZAKTIENGESELLSGHAFT, OF IBERLIN-TEMPELHOF. GERMANY WTRELESS SIGNALINGAPPARATUS Application filed March 11, 1929, Serial No. 345,914, and inGermany Kay 12, 1928.

In the construction of transmittersv and receivers for short andultra-short waves, special precautionary measures have to be taken,since all the oscillation circuits shrink to @quite unusually smalldimensions. For this reason, it is not possible simply to place anapparatus for the purpose of protection from external disturbinginfluences inside a metal casing and to earth the same. When operat- |1oing w1th longer wave-lengths, this is possible without difficulty, sincethe lead to the antenna can be simply led out from the casing in aninsulated manner in order to be connected to the'antenna. The antennacircuit I is, however, in devices for ultra-short waves, only severalcentimeters long and its entire energy would be taken from it if it werearranged in close proximity to the screening casing. Furtherdifliculties arise, for into stance, in aircraft stations, since thesmall antenna circuit must at all events be arranged outside the flyingmachine but longer leads to the same, cannot be attached. In this casetherefore, the whole apparatus had to be installed outside the flyingmachine, on which account however, the manipulation of the same wasimpossible. The disadvantages described are avoided, according to theinvention, by arrangin the circuits conveying low-frequency, me 'umfrequency and direct current, in a screened earthed metalcasing andmakmg the connection with the circuits conveying high-frequency whichare separated in space, galvanically y means of leads which are screenedby a metallic protective covering and which do not convey any hih-frequency. The figure in the rawing shows one form of my invention,with parts of the housings 40 broken away to diagrammatically disclosepart of the transmitter circuit.

In the drawing of the subject of the invention given by way of example,the highfre uency part is indicated by HF and the modulation orlow-frequency part by NF. The high-frequency transmitter given by way ofexample is connected in the manner usual.

with short-wave stations. The tunable oscillation circuit LG; isconnected, under the ino termediate connection of the usual condenser Gwith the anode and the grid of the valve R The anode voltage isintroduced to the neutral point of the intermediate circuit L. Thesupply conductors of the heating and anode current are bridged over bycapacities G and C, in order to prevent high-frequency flowing in thesame by making a short-circuit for high-frequency. The actualhigh-frequency transmitter is arranged inside a suitable casing, whichmayconsist of weatherproof material or insulati'n material, in orderthat it should be possib e also to arrange the transmitter somewhatoutside the flying machine already mentioned atithe beginning.

All the batteries in addition to the. modulation arrangement orkeying-arrangement are situated in an earthed metal casing G. A Heisinmodulation circuit is diagrammatically s own in the figure. Themicrophone must, of course, be outside the casing and is connected at M,in order to influence the grid ofthe valve R through a transformer U.The heating'batteries B and B in addition to the anode choke D arelikewise inside the casing. The connection with the high-frequency partis made by lines, which, in the example shown, are inside a flexiblemetal tube S which is connected with the casing G. It is obvious thatany desired modulation or keying arrangement can be arranged inside thecasing and that the connecting line together with the flexible metaltube can be adapted to be plugged in. For special purposes, it is alsodesirable to replace the flexible metal tube by a stiif tube and tocarry the high-frequency transmitter by means of the tube itself.

The separation, according to the invention, of the high-frequency partfrom the other parts can be carried out equally well in the case of areceiving apparatus. The wavelength of the transmitter can, of course,be firmly adjusted, but on the receiving side, a corresponding receivingapparatus must be used which need not be tuned in the highfrequencypart. Either a receiver which is little selective is used or asuperheterodyne receiver or super-regenerative receiver, the auxiliaryfrequency of which is conveyed to the high-frequency receiver likewiseby leads,

which are led in the flexible metal tube. It is unnecessary to explainthe circuit in more detail by aid of a figure, since in short-wavedevices, the transmitting and receiving circuit are the same inprinciple and well-known of themselves. It is also possible withoutdifiiculty, with particular receiving arrangements, to arrange themedium frequency part also in the metal casing.

, What I claim is:

1. Anapparatus for wireless signaling by ultra-short waves'comprisingtwo parts arranged in s aced relation to one another, the first of saiparts including the circuits for high frequency and the second of saidparts comprising a screened metal casing connected with earth andincluding circuits for lowfrequency and direct current; the said twoparts being connected galvanically through leads which are screened by ametallic protective covering, and condensers shunting said leads attheir connection points with the high frequency circuits.

2. An apparatus for wireless signaling by ultra-short waves comprisingtwo parts arranged in spaced relation to one another, the first of saiparts including the circuits for high frequency and the second of saidparts comprising a screened metal casing connected with earth andincluding circuits for medium, low-frequency and direct currents; thetwo parts being connected galvanically through I leads which arescreened by a metallic protective covering, and condensers shunting saidleads at their connecting points with the high frequency circuits.

3. An apparatus for wireless signaling by ultra-short waves comprisingtwo parts arranged in spaced relation to one another, the first of saidparts including the circuits for high frequency and the second of saidparts comprising a screened metal casing connected .with earth andincluding circuits for lowfrequency and direct currents; the two partsbeing connected galvanically through leads enclosed in a flexiblemetallic tube, and condensers shunting said leads at their connectingpoints with the high frequency circuits.

4. An apparatus for wireless signaling by ultra-short waves comprisingtwo parts arranged in spaced relation to one another, the first of saidparts including the circuits for high frequency and the second of saidparts casing enclosing the circuits for highrequency and the second ofsaid parts comprising a screened metal casing connected with earth andenclosing circuits for medium-frequenc low-frequency and directcurrents; the said two parts being connected galvanically through leadsscreened by a metallic protective covering, and shunt condensers at theconnection points of said leads with the highfrequency circuits.

In testimony whereof- I have affixed my signature. 9o

EDUARD KARPLUS.

comprising a screened metal casing connected with earth and includingcircuits for mediumfrequency, low-frequency and direct currents; the twoparts being connected alvanically through leads enclosed in a flexilflemetallic tube, and condensers shunting said leads at their connectingpoints with the high frequemgncircuits.

' 5. apparatus for wireless signaling by ultra-short waves comprisingtwo parts arranged in s aced relation to one another, the first of saiparts comprising a water-tight

